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Auteurs principaux: Clocchiatti, Alejandro, Rodríguez, Ósmar, Morales, Ariel Órdenes, Cuevas-Tapia, Benjamín
Format: Preprint
Publié: 2024
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Accès en ligne:https://arxiv.org/abs/2406.00273
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author Clocchiatti, Alejandro
Rodríguez, Ósmar
Morales, Ariel Órdenes
Cuevas-Tapia, Benjamín
author_facet Clocchiatti, Alejandro
Rodríguez, Ósmar
Morales, Ariel Órdenes
Cuevas-Tapia, Benjamín
contents An analysis of the Cosmological Constant $Ω_Λ$ fitted to subsamples of the Pantheon+ Type Ia SN sample spanning 2$π$ sterradians for a grid of 432 pole positions covering the whole sky reveals two large scale asymmetries. One of them is closely aligned with the Galactic North-South direction and the other points approximately towards RA$\sim 217.5^\circ$ Dec$\sim -26.4^\circ$, $\sim$50.9 degrees from the CMB dipole Apex. The signal to noise ratio (S/N) of the multiple $Ω_Λ$ measurements in these directions is $3.2\lesssim $ S/N $\lesssim 8.4$. The first asymmetry is puzzling, and would indicate a systematic effect related with the distribution of Pantheon+ SNe on the sky and, probably, how the correction for reddening in the Galaxy is calculated. The second one, which entails a 2.8-$σ$ tension between $Ω_Λ$ measure in opposite directions, bears strong implications on its interpretation as Dark Energy: It is consistent with the prediction for tilted observers located in a Friedmann-Robertson-Walker universe who could measure an acceleration or a deceleration with a dipolar asymmetry, irrespective of what the universe as a whole is doing. In this case, $Ω_Λ$ would not be a physical entity, a real Dark Energy, but an apparent effect associated with the relativistic frame of reference transformation.
format Preprint
id arxiv_https___arxiv_org_abs_2406_00273
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Global Anisotropies of $Ω_Λ$
Clocchiatti, Alejandro
Rodríguez, Ósmar
Morales, Ariel Órdenes
Cuevas-Tapia, Benjamín
Cosmology and Nongalactic Astrophysics
An analysis of the Cosmological Constant $Ω_Λ$ fitted to subsamples of the Pantheon+ Type Ia SN sample spanning 2$π$ sterradians for a grid of 432 pole positions covering the whole sky reveals two large scale asymmetries. One of them is closely aligned with the Galactic North-South direction and the other points approximately towards RA$\sim 217.5^\circ$ Dec$\sim -26.4^\circ$, $\sim$50.9 degrees from the CMB dipole Apex. The signal to noise ratio (S/N) of the multiple $Ω_Λ$ measurements in these directions is $3.2\lesssim $ S/N $\lesssim 8.4$. The first asymmetry is puzzling, and would indicate a systematic effect related with the distribution of Pantheon+ SNe on the sky and, probably, how the correction for reddening in the Galaxy is calculated. The second one, which entails a 2.8-$σ$ tension between $Ω_Λ$ measure in opposite directions, bears strong implications on its interpretation as Dark Energy: It is consistent with the prediction for tilted observers located in a Friedmann-Robertson-Walker universe who could measure an acceleration or a deceleration with a dipolar asymmetry, irrespective of what the universe as a whole is doing. In this case, $Ω_Λ$ would not be a physical entity, a real Dark Energy, but an apparent effect associated with the relativistic frame of reference transformation.
title Global Anisotropies of $Ω_Λ$
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2406.00273